A POS system may utilize an RFID system capable of collectively reading commodity code tags. In the RFID system, commodity codes of the commodities in a shopping basket are collectively read from the RFID tags attached to the commodities through an antenna of an RFID reader/writer.
In a case in which the RFID reader/writer uses a plurality of antennas, even if malfunction occurs in one of the plurality of antennas, the commodity code can still be read from the RFID tag located in a communication range of the remaining antennas. However, if the malfunctioning antenna is not identified, settlement processing is continued in a state in which the commodity code of the commodity located in the communication range of the malfunctioning antenna is not being read. After the settlement, the commodity for which the commodity code is not read may be taken out of the store without being accounted for in the settlement processing.